(AP Photo/Brian Melley). A poster at a news conference shows suspects captured and at large as authorities announce indictments against the Mexican Mafia in Los Angeles Wednesday, May 23, 2018. Leaders of the notorious Mexican Mafia "gang of gangs" wer...

The Los Angeles jails are run by the county sheriff, but the Mexican Mafia wields the power in the underworld behind bars.

The Los Angeles jails are run by the county sheriff, but the Mexican Mafia wields the power in the underworld behind bars.

(AP Photo/Carolyn Kaster, File). FILE - In this Thursday, May 17, 2018, file photo, U.S. President Donald Trump speaks during a meeting in the Cabinet Room of the White House, in Washington. Trump said he will "demand" that the Justice Department open ...

Trump's demand puts further pressure on the Justice Department, which later Sunday asked its watchdog to expand an existing probe of FBI actions, as the White House combats the threat posed by special counsel Robert Mueller's ongoing investigation.

Trump's demand puts further pressure on the Justice Department, which later Sunday asked its watchdog to expand an existing probe of FBI actions, as the White House combats the threat posed by special counsel Robert Mueller's ongoing investigation.